Purify T-cell derived antigen-binding receptors by using the response of A/J mice to the chemically defined antigen p-azobenzenearsonate. Further, the Contractor shall evaluate new procedures for detecting antigen-binding T-cells, comparing them with precedures currently in use. Investigate additional methods for clonal expansion of antigen specific T-cells, to obtain the largest number of cells for receptor extraction. Develop a standard procedure for specific purification of antigen specific T-cells, and establish preliminary procedures for extracting and characterizing T-cell antigen receptors.